Cross-back undergarment



FIG. 1 is a front right perspective view of a cross-back undergarment showing the new design;

FIG. 2 is a rear left perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a left side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines showing the mannequin depict environment and form no part of the claimed design. All other broken lines in the figures depict portions of the cross-back undergarment that form no part of the claimed design. 

CLAIM The ornamental design for an cross-back undergarment, as shown and described. 